Enhancement of methane production from anaerobic co-digestion of food waste and dewatered sludge by thermal, ultrasonic and alkaline technologies integrated with protease pretreatment.

Pretreatments to improve the efficiency of anaerobic digestion (AD) have gained more attention. The efficiency and mechanism of neutral protease (NP) integrated with other methods remain unclear. This study investigated the efficacy of thermal, alkaline and ultrasonic technologies integrated with NP as the pre-treatments for AD of food waste and dewatered sludge.